Feature: YAML Template Engine coverage boost for uncovered lines
  Targets uncovered lines 101-105, 134-136, 138-142, 172, 236-237

  Background:
    Given a fresh YAML template engine instance

  # ── Lines 101-105: fallback path returns a valid dict after _fix_common_yaml_issues ──

  Scenario: Fallback fix path returns a dict after first parse raises YAMLError
    Given a YAML template with Jinja2 that renders valid content
    And a context that produces parseable YAML on fix retry
    When I render and parse with a forced first-parse YAMLError returning a dict
    Then the fallback parse should return a dict result

  # ── Lines 101-104: fallback path raises ValueError when fixed YAML is not a dict ──

  Scenario: Fallback fix path raises ValueError when repaired YAML is not a dict
    Given a YAML template with Jinja2 that renders valid content
    And a context that produces parseable YAML on fix retry
    When I render and parse with a forced first-parse YAMLError returning a list
    Then a ValueError should be raised from the fallback path

  # ── Lines 134-136: _postprocess_rendered_yaml reaches value_words split branch ──

  Scenario: Postprocess reaches value_words splitting logic for single-colon line with spaced value
    Given rendered YAML with a single-colon line whose value has multiple words
    When I postprocess the YAML content
    Then the value_words branch should be entered and evaluated

  # ── Lines 138-142: dead code in postprocess (guard conflict prevents entry) ──
  # These lines are structurally unreachable due to conflicting guards on lines 128+133 vs 135-136.
  # We exercise the closest reachable branch and document the dead code.

  Scenario: Postprocess value_words inner condition evaluates False for no-colon values
    Given rendered YAML content "  key: alpha beta gamma" with spaces in value
    When I postprocess the YAML content
    Then the line should pass through unchanged because value words lack colons

  # ── Line 172: _fix_common_yaml_issues appends line with single or zero colons ──

  Scenario: Fix common YAML issues preserves a line with exactly one colon
    Given YAML content with a single-colon line "simple: value"
    When I apply fix common YAML issues
    Then the single-colon line should be preserved verbatim

  Scenario: Fix common YAML issues preserves a line with zero colons
    Given YAML content with a zero-colon line "no colons here"
    When I apply fix common YAML issues
    Then the zero-colon line should be preserved verbatim

  # ── Lines 236-237: _sum_filter raises ValueError for non-summable input ──
  # (pragma: no cover marked, but we exercise it anyway)

  Scenario: Sum filter raises ValueError for non-summable sequences
    Given a sequence of non-summable items
    When I call the sum filter on the non-summable sequence
    Then a ValueError should be raised with a descriptive message

  # ── Integration: end-to-end render that exercises fallback fix returning a dict ──

  Scenario: End-to-end render with mocked first-parse failure and successful fix
    Given a template "result: {{ val }}" with context val set to "ok"
    When rendering triggers a YAMLError on first parse but fix produces a dict
    Then the final result should be the fixed dict